1. Field of the Invention
The present invention relates to the detection and quantification of specific molecular interactions such as nucleic acid hybridization, antigen-antibody reaction, receptor-ligand interaction and other specific molecular interactions through the use of small beads, preferably aggregated beads for ease of detection, and the detection by various physical and chemical means. This invention is widely applicable to medicine, industry—both civilian and defense, environmental monitoring and scientific research.
2. Description of the Related Art
Nucleic acid hybridization, antigen-antibody reaction and receptor-ligand binding are examples of molecular interactions, which because of the specificity of the interaction, are of tremendous value in the identification, or detection of these substances. Such specific molecular interactions can be detected by various means, with different sensitivities and specificities, involving target or signal amplifications. Amplification for antigen-antibody reaction is based on signal amplification, such as by enzymatic reaction. Nucleic acids can be detected by both signal amplification and target amplification through the polymerase chain reaction (PCR). Although PCR is extremely sensitive, it is laborious and not consistently precise. Additionally, because PCR requires multiple cycles of melting, annealing and extension, it needs to take at least one hour. Recently, real-time PCR has improved the endpoint detection, thereby reducing the period to accomplish the process. Nevertheless, cycling is still required. In addition, techniques that enhance the sensitivity and specificity of target nucleic acid amplification in an isothermal environment have been introduced.
Hence, it is desirable to develop a simple, inexpensive process and apparatus which can eliminate the need for target amplification and to speed up the overall process of detection of molecular targets.